Flood Hazard News

Vol. 35, No. 1 December, 2005 A Brief History of the Walled Section of Cherry Creek By Mark Hunter, PE: Bill DeGroot, PE and Dave Lloyd, PE

Robert Speer was elected Mayor of expressed concern about the leakage visible at the Kennedy Golf course. Denver in 1904. His administration and flood safety of the structure. One of began a period of dramatic civic the primary issues with Castlewood Flood control specialists quickly improvement including efforts to Dam was the fact that this on-stream recognized the inadequate capacity of control flooding on Cherry Creek. reservoir served its irrigation purposes Kenwood Dam and by 1940 federal Between 1906 and 1911 parallel best when it was full of water. This left agencies were planning its replacement concrete walls 10 feet tall and 80 feet little room for floodwater storage and with what would become the current apart were constructed from Downing meant that the spillway system was Cherry Creek Dam. Land was acquired Street to Blake Street to contain Cherry regularly called into use. in 1946 and by 1950 the new structure Creek. The termination of the walls at was in operation. In mid-June 1965 the Blake Street left the lower half-mile of The fear of the residents of Denver Cherry Creek Dam proved its worth Cherry Creek uncontained. became reality in early August, 1933 when it impounded the largest flood in when a series of summer the area's history while the uncontrolled The flood of July 14, 1912 inundated thundershowers completely filled the South Platte River delivered an the lower portion of the city and put reservoir, overtopped the dam, and unprecedented flood to Denver. three feet of water in Union Station. eventually breached the structure. The impact of this flood hastened the Thirty five miles downstream in Denver In the years that followed, the channel completion of the concrete walls the the flood tore out some of remainder of the way to the South Platte the concrete channel River. With the flood of 1912 still in walls, and put a foot of mind the dimensions of the walls were water on the floor of increased to a height of 12 feet and a Union Station. width of 88 feet. This final section was completed in 1914. These walls are still The 1933 flood forced in service and provide a continuous the City of Denver to walled channel for Cherry Creek for the develop a comprehensive 3.2 miles from Downing Street to the flood control plan for South Platte River. Cherry Creek. This local effort resulted in the Castlewood Dam was constructed on construction of Kenwood Cherry Creek just south of Franktown in Dam beginning in 1935. 1890 by a private organization for the It was located near the purpose of providing irrigation water. intersection of Hampden Ownership of the dam changed several Avenue and Havana times over the years but its purpose was Street just downstream of always to support the development and the current Cherry Creek sale of irrigated farm and ranch land in Dam. A few remnants of Douglas County. Observers the concrete components downstream in Denver quickly of Kenwood Dam are still The 1933 flood in the walled section of Cherry Creek fell into disrepair, heavily overgrown maintenance/recreation trail. with vegetation and a dumping ground However there were two areas for broken concrete, asphalt and other where the plan proposed debris. It was an eyesore, had lost much removing the walls to create of its flood carrying capacity, and was expanded park areas extending certainly no asset to the community. from creek level to street level. One site was at approximately In 1975 the Urban Drainage and Flood Larimer Street to Lawrence Control District, City and County of Street, and the other was near Denver, City of Glendale and Arapahoe the confluence with the South County embarked on an ambitious effort Platte River. Ultimately a to master plan the Cherry Creek corridor version of the former was from the South Platte River to Cherry constructed (see below) but

Creek Dam. The master plan was to the other site was lost to new include flood control, recreation and development. transportation. The consulting team of Merrick and Co. and Harman, In the early 1980’s the City O’Donnell & Henninger Associates and County of Denver (HOH) was selected by the sponsors to received discretionary Federal develop alternative scenarios, seek grant money, and then Mayor public input, and prepare a master plan Bill McNicholls allocated for the corridor. these funds to implementation of the flood control and trail Transportation issues ultimately could plan in the walled section of not be resolved to the satisfaction of the the creek. This construction three local government sponsors, and, in effort provided the basic order to get the flood control and channel, trail and access ramp Top. Artist’s concept from the master plan. recreation elements of the plan configuration that would form Bottom. The channel following initial completed, the transportation portion the framework for several construction. was dropped. subsequent projects which are described below. The flood control study revealed that primarily boulder edging but also even with Cherry Creek Dam Two design decisions were made that included riprap protection and a couple constructed upstream, a large 100-year led to the need for later adjustments. sections of interlocking articulated flood hazard area existed through the The first was to take the trail out of the concrete blocks. By 1991 low flow neighborhoods adjacent to the walled bottom of the creek for stretches of channel protection was in place on section, including the Country Club several blocks where no traffic conflicts about 34% of the 3.2 miles of the walled neighborhood areas of downtown, and existed, in order to keep some areas of section of Cherry Creek. portions of the new Auraria campus. A the channel bottom more natural for major goal of the study became to wildlife habitat. However, walkers, In 1989 a bond issue was passed by the contain the 100-year flood to the runners and bicyclists quickly decided Denver voters which included funding channel. to stay in the bottom and wore trails for the urban redevelopment of Cherry through the intended habitat. In 1982 Creek from Colfax Avenue downstream The master plan was completed in 1977. the two gaps in the Cherry Creek trail to Market Street. This project became a Within the walled section the plan corridor where filled. About 3000 feet public/private partnership when the called for cleaning out the vegetation of eight foot wide concrete was installed Downtown Denver Partnership and the and debris, reshaping the bottom of the to complete the trail corridor within the Urban Drainage and Flood Control channel, installing a number of drop walled section of the creek. District joined Denver in the effort. The structures to control the channel grade, resulting project, known as CreekFront, and installing a number of access ramps The other decision was to not line the revitalized Cherry Creek as an urban and a maintenance access trail that low flow channel. Over time we began greenway while preserving the flood would also be used as a recreational to see severe erosion and migration carrying capacity. The project included trail. Two stair cases were also problems and had to address those two drop structures, including one included. problems with bank stabilization formal grouted boulder drop, a second measures as a function of the District’s (Continued on page 5) Most of the other proposed park Maintenance Program. Six phases of improvements involved new parks low flow channel bank protection were outside the channel walls but close to completed by the Maintenance Program the creek, and connected to the between 1984 and 1991. This work was

2 Lloyd’s Look

by Dave Lloyd

Timely Comment from the District's Executive Director

How fortunate we are to live in the State for the purpose of enhancing the United Competition for the every decreasing of Colorado. This has never been more States's resilience and reducing our tax dollar is always a daunting task for in evidence than over the past year as vulnerability to natural and flood control managers. we've witnessed several natural technological hazards. disasters of epic proportions. Even though the Katrinas and Ritas of As was evidenced along the gulf coast, this past year go a long way in keeping I was just recently reading the cover our communites are still challenged by us focused upon the arena of sound story in the November 2005 issue of disaster preparation, response and floodplain management, mankind has "Natural Hazards Observer." The recovery. Although lives lost to natural always proven itself to have a short article points out that in the last year disasters each year have been reduced, memory (he says as he sits here trying alone, we've experienced a multitude of the annual cost of major disasters to remember what he had for breakfast). disasters including winter storms, continues to rise. The Subcommittee on wildfires, floods, tornadoes, landslides, Disaster Reduction identified four key In the words of Paul Danish, former and most recently Hurricanes Dennis, characteristics of disaster-resilient Boulder County Commissioner and Katrina, and Rita. Although not directly communities: Director on the District's Board when affecting the United States, the • Relevant hazards are asked if a devastating flood could occur earthquake and tsunami in the Indian recognized and understood one day along Boulder Creek: "Not Ocean last December claimed over • Communities at risk know only yes, but hell yes." 240,000 lives across 12 countries and when a hazard event is injured, displaced or otherwise impacted imminent Organizational and Staff Changes millions. • Individuals at risk are safe This past year we were pleased to create from hazards in their homes a new program area within the District In light of this past years events, and places of work organization. Kevin Stewart was disaster reduction has once again moved • Disaster-resilient communities selected to be the Manager of the to the infamous "front burner." One experience minimum District's new Information Services and product of this has been the report from disruption to life and economy Flood Warning Program. Earlier this the Subcommittee on Disaster after a hazard event has passed year we hired Chad Kudym to assist Reduction, part of the President's Kevin in this new program. Chad National Science and Technology From a flood control professionals brings to the District a wealth of Council, entitled "Grand Challenges for perspective, these are all very enviable knowledge and experience in the GIS Disaster Reduction." The report was goals to strive for in the area of arena and we are pleased to have him on prepared in an effort to establish a floodplain management; however, staff (even if he is a Cornhusker). framework for future government identifying the course of action is only investment in science and technology the first step in the process.

Kudym joins District staff previously employed by HDR Chad Kudym has joined the District as a Engineering in Denver where he served Project Engineer for the Information as their GIS coordinator. He is a much- Services and Flood Warning Program. welcomed addition to our staff as we Chad has a B.S and M.S. Degree in continue improving our GIS and flood Geography from the University of warning capabilities. Chad is also an Nebraska. He is also a CFM (certified experienced web designer and familiar floodplain manager), a national with various modern information professional certification program technologies. His handiwork is clearly administered by the Association of State evident in the article describing ALERT webserver enhancements. Floodplain Managers. Chad was

3 Master Planning Program Notes By Ben Urbonas, P.E., Manager, Master Planning Program Planning Projects Four planning projects were completed STATUS OF PLANNING PROJECTS in 2005; 15 projects were under way; Project Sponsor(s) Consultant Status and we hope to begin 4 new planning Lower Brantner Gulch Adams County, Thornton Love & Completed in 2005 projects in 2006. Assoc. Third Creek (Lower) MP Adams Co., Commerce City, Kiowa Completed in 2005 Updates Brighton We now have a total of over 129 Kinney Creek & Fonder Douglas Co. WRC Completed in 2005 completed watershed-level major Draw drainageway and outfall system plans in Second Creek Update Commerce City, Adams Co. Kiowa Completed in 2005 our inventory. Some of these are Denver Criteria Update Denver Wright Water 98% Complete updates of master plans completed in Douglas Co., Arapahoe Co., Douglas Co., Arapahoe Co., Muller Eng. 90% Complete the past. Centennial Criteria Update Centennial Broomfield & Vicinity Broomfield & Westminster Kiowa 98% Complete Urban Storm Drainage Criteria Upper Goldsmith OSP Arapahoe Co. Greenwood Moser Assoc. 98% Complete Village, Centennial Manual Massey Draw & SJCD (S) Jefferson Co., Arapahoe Co. n/a 98% Complete We no longer publish our Urban Storm Yankee Doodle OSP Arvada n/a 90% Complete Drainage Criteria Manual (USDCM) in Lemon and Scott Gulch Douglas Co. CH2MHill 65% Completed printed form. All three volumes of this OSP manual and all of the updates to these Four Mile Canyon & Boulder. Love & 65% Complete Wonderland Cr. Updates Associates three volumes are posted on our web Toll Gate Creek Hydrology Aurora Kiowa 60% Completed page , namely, www.udfcd.org. You Coal Creek in Superior Superior n/a 60% Complete may download any of these free of Brighton Watershed Update Brighton WRC 30% Complete charge. You can choose to download Murphy Creek Update Aurora Moser Assoc. 20% Completed each volume in its entirety via a self- Big Dry Cr. (AdCo) North Thornton, Adams Co., Wright Water 15% Completed extracting Zip file or each chapter Tributaries Update Broomfield Clear Creek Update Wheat Ridge, Jefferson Co., n/a Mapping under way individually. Each chapter is marked Adams Co., Golden, Denver with the revision date to tell you if the Dutch Cr./Lilley G. Update Jefferson Co., Denver, n/a Mapping under way one you have is current. Lakewood Hoffman Drainage Adams Co. & Thornton n/a Mapping under way We encourage you to check for latest Brighton Detention Brighton n/a Start in 06 Reassess updates to the manual and related Lena G. Update d/s of Wheat Ridge n/a Start in 06 materials on a regular basis. New Maplegrove Reservoir updates to the manual and new versions Little Dry Cr & Greenwood Douglas Co. Centennial, n/a Start in 06 of the software, spreadsheets, and Gulch u/s of Holly Greenwood Village, Lone Tree, S. Suburban Parks AutoCAD drawings to assist you with Cottonwood Cr. W.Q Arapahoe Co., Centennial, n/a Start in 06 the calculations and design can be Update CCBWQA, Lone Tree, posted at any time. We try to e-mail as Douglas Co. many people that we have on record of in the manual. The technical issues spreadsheets for the design of major new posting, but there is no supporting porous pavement design and stormwater inlets, analysis of street flow guarantee that any individual or maintenance are quite complex and we and detention basins. If you have not company will get such a notice because have yet to see how these types of yet had a chance to download these our record may not be complete or out designs will succeed and survive over spreadsheets or others, I urge you to do of date. time. As a result, we are treating these so. Ken, in cooperation with many criteria as interim and may adjust them cities and counties within the District is By the time you read this article, based on experience with earlier negotiating with Colorado State another significant revision to Volume 3 installations. Our goal is to come up University to do scale modeling for the will probably be posted on our web site. with technical recommendations for types of inlets used in the Denver In addition, several smaller revisions to porous pavements that best fit the region. We hope this will improve on Volumes 1 and 2 are in the pipeline. climate and the conditions found in the design guidance that is in practice eastern high plains of Colorado and today. We now hope to have this A major revision was posted in 2005. regions having similar climatic and testing program under way in 2006. The porous pavement sections of the geologic (i.e., soil) conditions. Structural BMPs Chapter of Volume 3 District’s Software were totally rewritten. Instead of one Ken MacKenzie of the Design and We have completed our effort to type of porous pavement, criteria for Construction Program has authored integrate the District’s CUHP software five types of porous pavement are now another major revision of the

4 into a new, Windows-based, EPA’s be downloaded free of charge form our Douglas and Arapahoe Counties SWMM 5.0. website. However, the work continues Criteria Manual Update Project and we hope to add capabilities in the The District continues to work with the For the last two years EPA has been future to CUHP 2005, such as ability to preparation of updated stormwater working on rewriting the SWMM perform continuous simulation. In criteria manuals for Douglas and software and to provide a graphical user addition to the above, new versions of Arapahoe Counties. The consultant for interface (GUI). Go to the web page UDPOND and UDSEWER that contain this project is Muller Engineering http://www.epa.gov/ednnrmrl/swmm to corrections and updates are now Company. Since the project began in download this software free of charge. available for downloading. 2003, the Cities of Centennial, Lone The District’s new CUHP 2005 model Tree and Castle Rock have joined this now interfaces with the EPA’s model District’s April 2005 Seminar effort. At this time the final versions of and we no longer will support the old Again our annual seminar series this manual are expected to be released versions. continues to be successful when in early 2006. measured by attendance. On April 28, The CUHP model works with the new of 2005, we held a seminar titled: Denver is updating it Stormwater EPA’s software in a similar fashion as Emerging Technologies and Practices Design and Technical Criteria the old version, namely, it generates in Urban Stormwater Management. It Denver’s Wastewater Management runoff hydrographs that are then routed was attended by over 230 participants Division has launched an effort to by SWMM 5.0. The new version, titled from municipalities, federal and state update its Stormwater Design and CUHP 2005, relies on Microsoft Excel governments, consultants and other Technical Criteria. The District has for the preparation and editing of input organizations. The proceedings are been managing this project and is data and manage the output. It also available at: working with Denver and Wright Water provides a converter to convert the older http://udfcd.org/conferences/conference Engineers, Inc., the project’s consultant. CUHP and UDSWM inputs to run under s.htm At this time look for the release of the the new software. This model may also completed manual early in 2006.

Cherry Creek (from page 2) Phase 1 of Punt the Creek began at Broadway. Another ramp was installed trail for pedestrians only, a block long Market Street which was the by Denver at the upstream end of the downstream end of the CreekFront walls and yet another one is planned for area where the walls were removed and th a formal park was created and project. The lower end of phase 1 was 2007 near 12 Avenue. installation of an additional 3150 feet of at Delgany Street. It was built in 1994 low flow channel protection. and included 1650 feet of Cherry Creek. Today the walled section of Cherry Construction of CreekFront was Creek will contain the 100-year flood. completed in November, 1992. Phase 2 of Punt the Creek went the It also contains a three-mile grade remaining 1450 feet from Delgany separated trail. In the downtown area, The redevelopment of Cherry Creek Street down to the confluence with the which is the highest use area, continued in 1994 with the creation of South Platte River and was finished in pedestrians and bikes have separate the Punt the Creek project. The purpose 1998. Both phases of this project trails. The trail in the walled section is of this project was to make the lower included lining the low flow channel to the busiest stretch of trail in Colorado. 3100 feet of the creek usable for small protect against erosion and extending flat-bottomed boats called punts. Punts the pedestrian trail. Two additional are about four feet wide and draw 6" to access ramps 8" of water while seating 4 adults. They were also are powered and steered by the operator included. using a long pole. Access ramps The punts travel up and down the creek were installed on on temporary "lakes" created by either side of the inflatable hinge crest dams with locks creek between for boat passage. Four sets of locks and Broadway and five hinge crest dams were required to Lincoln when make this 3100 foot section of Cherry the south bound Creek boatable. The dams are inflated lanes of Speer in the morning to create the lakes and Boulevard were deflated at night to allow full flow of placed in a the creek. tunnel under Lincoln and CreekFront park with water wall and public art in background.

5 Design and Construction Program Notes By Paul Hindman, P.E., Manager, Design and Construction Program

In 2005, the Design and Construction Status of Current District Construction Projects program continued to assist local Participating Design Constructio Construction governments in designing and Jurisdiction(s Status n Status Cost building many major flood control Project Name ) (% (% (X $1000) projects. Internally, we divide the complete complete) responsibilities amongst our staff by ) political boundaries. Laura Kroeger is in charge of Boulder, Adams and Adams County Broomfield Counties, Ken Mackenzie Brantner Gulch Adams 10 0 Dahlia/Kenwood Outfall Adams 25 0 is responsible for Denver and Globeville Outfall Adams 30 0 Jefferson Counties, and Paul Grange Hall Floodplain Delineation Northglenn 100 NA Hindman watches over Douglas and Hoffman Drainageway Adams 30 0 Arapahoe Counties. Kalcevic Gulch-Dam Adams 100 100 590 McKay Pond Adams 100 0 McKay Pond: Outfall Adams 100 0 Throughout the entire program, in Niver-Trib L @ Pecos St. Federal Heights 100 2005 we committed 6.8 million to North Outfall - Baseline Road Brighton 75 0 projects. As shown in the attached School Trib. Thornton 50 0 table, the Design and Construction Silverado II Detention Pond Aurora/Denver 100 0 Program continues to manage over 80 Utah Junction/Clay Street Outfall Adams 10 0 projects. Some have been ongoing Arapahoe County for many years with multiple phases Big Dry Creek: Allen WTP LOMR Englewood 95 NA while others are just getting started. Big Dry Creek Maintenance Trail Englewood 50 0 Cherry Creek: Drops #20 & #21 Arapahoe County 90 0 Cherry Creek: Maintenance Access Arapahoe County 100 0 A couple of projects deserve special Cherry Crest West Centennial 100 100 376 recognition. One of those is the Granby Ditch Inlet Aurora 75 0 Littles Creek project in Littleton. Holly Hills Detention Arapco. 100 0 Laura Kroeger, the District’s Project Little Dry Creek at Arapahoe Road Centennial 95 0 Little's Creek: Broadway to Apache City of Littleton 100 100 Engineer assigned to the Project, was Normandy Gulch Columbine Valley 10 0 responsible for administering the Parker/Jewell Arapco. 100 100 1010 construction aspects of the project. Parker/Mexico: Phase 2 Arapco. 100 95% Piney Creek: u/s of E-470 (Sampson This was the third phase of Aurora 95 0 improvements to Littles Creek Gulch) Quebec / Iliff Outfall Arapco 100 0 (between Broadway and Apache Quincy Reservoir Drainage Aurora 100 0 Road) that Urban Drainage and the Sable Detention Aurora 10 0 City of Littleton teamed up with Sand Creek Aurora 100 90 4,100 engineers from ASCG, INC. and Southwood Village Outfall Centennial 5 0 constructors from Flatiron Utah Park Aurora 30 0 Constructors, Inc. to improve the Boulder County drainageway along the center of Drainageway G-Phase 2 Louisville 5 0 Elmer's Two Mile Greenway Project Boulder 20 0 Sterne Parkway in Littleton. The Phase I $703,000 project lasted six months Erie Reach BP20 Erie 30 0 Erie Regional Detention Facility No. and was completed in September. Erie 100 0 1045 Erie Regional Detention Facility No. Erie 50 0 Following completion of this last 1026 phase, all structures between Elati Valmont Bridge on South Boulder Creek Boulder County 100 0 Street and Apache Road will have Wonderland Creek Diagonal Hwy Boulder 100 50 been removed from the 100-year Broomfield County Broomfield/ floodplain. The first two phases in Quail Creek LOMR 90 NA the project consisted of replacing the Westminster bridges of several street crossings, Douglas County and of course, channel improvements. Cherry Creek: Apache Plume Parker 95 0 Cherry Creek: Stroh Ranch Parker 5 0 Phase 3 focused on collecting the Happy Canyon Creek-Phase 2 Douglas County 90 0 upstream storm water plus the local Little Willow Creek Douglas County 100 100 storm sewer flows into a 100-year Marcy Gulch: Upstream of Broadway HRMD 100 100 crossing under Sterne Parkway. It Newlin Gulch @ W. Parker Rd. Douglas County 90 0 was designed with a three-sided

6 precast box and a cast-in-place slab & Denver County low-flow channel, several storm 27th Ave. / Federal Blvd. OSP Denver 100 NA 30th & Magnolia Phase II Denver 100 25 sewer improvements ranging from Cherry Creek: Drop No. 24 Denver 100 10 18" to 48" RCP, and a new Globeville / Utah Junction-Phase 1 Denver 100 0 intersection with curb, gutter and Goldsmith Gulch Retrofit Denver 50 0 sidewalk. Amcor produced the 175 Harvard Gulch/University-Hills-Phase 1 Denver 75 0 linear feet of 28' wide by 5' high side Lakewood Gulch: 10th Ave. bridge Denver 100 10 Lakewood Gulch: Tennyson - Sheridan Denver 30 0 boxes while Flatiron used a 300-ton Lakewood Gulch: Tennyson Bridge Denver 100 100 1,400 hydraulic crane to place the boxes Lakewood Gulch: Wolff Bridge Denver 75 0 (see photo). Notably, the boxes were Montclaire OSP Denver 75 0 placed in less than two days without Park Hill Phase III Denver 100 0 complication. University / Mexico OSP Denver 100 NA Jefferson County The second project of note for 2005 Arvada Channel Arvada 100 0 Bear Creek at Morrison Morrison 100 100 was the Tennyson Street Bridge Lakewood / Coyote Gulch 50 0 across Lakewood Gulch. Ken Jeffco MacKenzie oversaw this project for Green Mountain Drainageway B Lakewood 85 0 the Urban Drainage and Flood Hays Lake Outfall Arvada 95 0 Control District who partnered with Kenney’s Run Golden 100 0 2,000 Lakewood Gulch u/s Van Gordon Lakewood 100 100 242 the City and County of Denver to Lakewood Gulch-Welchester Park Jeffco 5 0 complete yet another flood control Lena Gulch: 10th Ave. through Orion St. Jefferson County 100 50 project on Lakewood Gulch. This was Lena Gulch-Isabell Jeffco 50 0 the third bridge replacement along the Lena Gulch-Mountainside Jeffco 100 100 1,391 gulch and was completed in July of Leyden Dam Arvada 100 95 1,576 Massey Draw-Wadsworth Jeffco 100 100 240 this 2005. To see this 1.7 million Raccoon Creek Jeffco 10 0 dollar project a success, civil Ralston Creek LOMR Arvada 100 NA engineers and landscape design South Lakewood Gulch: CCU Detention Lakewood 95 0 specialists teamed up from select Pond consulting firms such as Kiowa Van Bibber Arvada 100 80 9,174 Engineering, Bates Engineering, and Other Projects Design Concepts. The single span Storm Sewer Inlet Study All 5 NA bridge replaced a 7' by 6' box culvert, and has the capacity to pass the 100- year flood. The bike trail parallels Lakewood Gulch underneath the bridge, compliment to the surrounding area. eliminating the on-grade crossing This feature is just another part of the currently in place. Also, the channel was new improvements Design and lined with grouted flagstone, a definite Construction continues to test out in the Denver area.

Littles Creek at Apache Road. Tennyson Street Bridge at Lakewood Gulch

7 Floodplain Management Program Notes By Bill DeGroot, P.E., Manager, Floodplain Management Program

Program reorganization appeal period is set to begin on January We completed a DFIRM maintenance In January a new program, Information 1, 2006. pilot project, using the Broomfield Systems and Flood Warning Program DFIRM to get a feel for what is was established. Kevin Stewart moved A Jefferson County DFIRM was involved in map maintenance, including from the Floodplain Management completed by Michael Baker, Jr. in incorporating new LOMRs into the Program to become manager of this new 2003. Unfortunately, it was completed DFIRM, adding new information to the program, and he took the flood warning in NGVD 29 datum, while the other base map, adding a new floodplain to activity with him. DFIRMs have been converted to NAVD the DFIRM and adjusting to receipt of 88. The District has received a more accurate data. Our report to The remaining major activities within $240,000 grant from FEMA, to be FEMA on this project is on our web site. the program are interfacing with the matched by $30,000 each from the National Flood Insurance Program, District and CWCB, to convert the Floodplain delineation maintenance eligibility, flood hazard Jefferson County DFIRM to the new We completed two flood hazard area area delineation, master plan datum. This is probably not enough delineation (FHAD) studies this year: implementation by others and public money to complete all of the required South Platte River in Adams County, information. work and publish new panels, but it will and Upper Goldsmith Gulch in be a good start. Arapahoe County, Our maintenance eligibility program continues to flourish under David While we are at it we will use digital We have FHADs underway for Clear Mallory’s direction. See David’s flood hazard area delineation study Creek through Adams County, Clear column elsewhere in this issue. reports completed or underway to Creek in Jefferson County, Massey Following is a discussion of significant supplement or replace older data sources Draw and SJCD (South) in Jefferson accomplishments in the other areas. in the DFIRM. This will include County, and Dutch Creek and Ralston Creek, Leyden Creek, Massey Tributaries in Jefferson County. DFIRM conversion projects Draw and North Tributary, SJCD In late 2003 we began Digital Flood (South) and Tributaries, Clear Creek, All of these studies are prepared in Insurance Rate Map (DFIRM) and Dutch Creek and Tributaries. digital form compatible with FEMA’s conversion projects for the City and Consultant selection for this effort was DFIRM specifications, and have been or County of Denver and Northern underway at the time this was written. will be incorporated into the appropriate Douglas County. The Douglas County Work should begin in January. DFIRMs. DFIRM became effective on September 30, 2005 and the Denver DFIRM Realistically, by September, 2006 we Implementation efforts became effective November 17, 2005. should have all of the District’s area Implementation of portions of our covered with DFIRMs. Our next master plans, particularly regional The Boulder County DFIRM conversion challenge will be to convince FEMA to detention facilities, is always a is being managed by the CWCB. The delegate to the District the responsibility challenge. We are currently negotiating contractor is PBS&J. Revised for maintaining all aspects of the an Intergovernmental Agreement (IGA) preliminary maps have been provided to DFIRMs for the District’s seven with Denver and the Rocky Mountain the local governments. The expected counties, including base map revisions, Arsenal (RMA) for the construction, effective date is September 30, 2006. Letters of Map Revision (LOMRs) and operation and maintenance of a number new floodplain delineations.. of facilities on the RMA. We are also Last year we received FEMA DFIRM negotiating an IGA with Denver and conversion grants of $480,000 each for LOMC pilot project Aurora regarding the implementation of Adams County and Arapahoe County. On July 1, 2001 we began a pilot project regional detention facilities in the Upper The District has contributed $70,000 for with FEMA to assume the responsibility Second Creek watershed. each county and the CWCB has to review requests for Letters of Map contributed $50,000 each. Change for the 32 communities within David Mallory’s column includes an the District that are participating in the example of a private sector The contractor for Adams County is National Flood Insurance Program. We implementation project. ICON Engineering, and for Arapahoe begin 2006 with a new grant to continue County it is Merrick and Co. the project Our final reports to FEMA FasTracks Coordination Preliminary maps and Flood Insurance on the results of the first three years are Last year voters in the Denver metro Studies for each county were distributed available on our web site. The fourth area approved a proposed sales tax to the local governments for comment year report will be posted in early 2006. increase (called FasTracks) for the on September 30. The formal 90-day

8 Regional Transportation District (RTD) Jefferson County on the way. Major have also discussed the next three to add over 100 miles of new light rail, conflicts will be encountered at the corridors with RTD representatives. commuter rail and bus rapid transit South Platte River, Lakewood Gulch corridors to its system. As you can and Dry Gulch. Check these out on our web site imagine, these transit corridors will We have a photo album showing what cross, or in some cases parallel, many We have been meeting frequently with we consider to be good examples for major drainageways, requiring close RTD and local government officials to others to emulate. We also have an coordination to minimize potential coordinate the potential implementation Activity Summary map that identifies conflicts. of District master plans in these areas in all District studies completed or in coordination with and ahead of the rail progress. We update the status of all The first corridor scheduled for construction. our studies quarterly. It would be a implementation is light rail along the good idea for anyone working on a West Corridor. It extends from We have established a West Corridor drainage study in the District to check downtown Denver to Golden, passing working group that meets monthly, and this map for existing or on-going studies through Denver, Lakewood and that might affect their work. Stormwater Permitting Support Activities By John T. Doerfer, Project Hydrologist, Master Planning Program

The District hosted quarterly meetings BMPs, such as Homeowner subject to a comprehensive evaluation to discuss stormwater issues in 2005. Associations, as well as local of its stormwater management programs These meetings served as a forum to government staff. for permit compliance by the U.S. exchange ideas, set up workgroups, and Environmental Protection Agency. report on accomplishments. Activities Low Impact Development. Miranda Results of this audit should be available of this group in 2005 are described Maupin with the City of Seattle Public in 2006. below. In addition to the local Works Department made a presentation governments within the District, a on opportunities for retrofitting low- Stormwater Monitoring. The District number of other cities, counties, and impact development BMPs into urban manages a storm-event monitoring special districts throughout Colorado settings. program of the South Platte River and that are required by law to have Clean tributaries for Aurora, Denver, and Water Act permits for their municipal Grand Valley Stormwater Utility. Lakewood. The U.S. Geological separate storm sewer system (MS4) Mesa County and the City of Grand Survey collected water-quality samples discharges actively participated in these Junction described their current for a total of seven storms in 2005. meetings. management programs and efforts to form a stormwater utility among various The District’s program to monitor and Municipal Operations Video. A 20- entities in the Grand Valley. test structural BMPs continued in 2005. minute video showing best management Seven storms were sampled at an practices (BMPs) for municipal shops, Arvada’s Public Education Program. extended-detention basin at Grant fueling areas, public streets, and de- Sandra McDonald shared the Ranch (Photo), nine storms at a porous- icing operations was created for comprehensive public education concrete pavement site in Lakewood, educational purposes. This video is program developed by the City of and four storms at an underground sand available for purchase through Excal Arvada, including their mascot “Fillip filter in Lakewood. Visual in Boulder at A. Can” with the message to dispose of www.excalvisual.com. trash properly.

Power Washing Brochure. Proper Industrial Activities methods for disposing water used for Brochure. Aurora, power washing of equipment, kiosks, Denver, Lakewood, bleachers, buildings, etc. was developed and the District under the leadership of Kevin Lewis, prepared a booklet and City and County of Denver. This poster for industrial brochure will be printed in 2006. and commercial activities as part of BMP Operation & Maintenance. MS4 permit Guidance on operation and maintenance requirements in 2005. (O&M) of structural BMPs was initiated in 2005. When completed in 2006, EPA Compliance these O&M guidelines and will be Inspection. The City useful for private owners of structural of Lakewood was

9 Maintenance Program Activities By Mark R. Hunter, P.E., Manager, Maintenance Program

The Urban Drainage and Flood Control Construction Activities contributing factor appeared to be District (District) Maintenance Program In 2005 $4,942,000 of work was inadequate energy dissipation as the committed a total of $5.6 million in performed under our various creek discharged from the culvert under 2005 to maintaining drainageways in the construction contracts. The smaller I-25. A drop structure near I-25 has Denver metropolitan area. The bulk of projects typically address isolated been rebuilt and others added in order to the drainageways we maintain are open drainage problems where the control the erosion. The channel has channels with native-grass-lined banks, construction will cost from a few also been regraded and a trail has been riprap or vegetative erosion protection, hundred dollars up to $200,000. Within added. and rock or concrete grade control this cost range seventy-nine individual structures. activities were completed under our High energy at culvert outlets appears to restoration contracts. Projects in this contribute to erosion at other sites as Our maintenance work covers the category of work are directly awarded to well. On Kettle Tributary to Willow spectrum of drainageway work. It a single contractor or bid among all Creek west of Yosemite Street in includes debris pick-up and mowing, contractors from our group of six Centennial we rebuilt the outlet area and localized repair to damaged and eroded contractors who have won open-ended regraded the area downstream. channels or detention facilities, and contracts with the District. A major Similarly, on Little Dry Creek between consultant-designed rehabilitation to advantage of work under the open- Hoyt and Kipling in Arvada, the erosion long reaches of deteriorated ended contracts is the ability to use them we repaired was worse immediately drainageways. to react quickly to local drainage needs. downstream of roadway crossings.

Mowing and Debris Pick-up When project construction will cost The low flow channel of Cherry Creek For the year 2005 we awarded nine more than $200,000 the work is is confined between vertical concrete contracts for debris pickups and native- designed by a private consultant and walls for its lower three miles before it grass mowing under our routine then put out for public bid to be built by joins the S. Platte River. Over the past maintenance program. Five contracts a private contractor. These larger 20 years we have placed thousands of were awarded through a competitive bid projects typically address severe linear feet of boulders to reduce bank process in March. The remaining four problems that have occurred on erosion. Recently we have also installed contracts were awarded as renewals of previously improved urban wrapped soil lifts to control bank the prior year contract. The value of drainageways. Fifteen large projects erosion of the low flow channel. each of these renewed contracts was were at various stages of design or Getting the vegetation to take hold in adjusted to match the movement in the construction during 2005. Our major the soil lifts requires determination, but regional Consumer Price Index over the projects for the year are summarized in so far the installation has performed prior year. the accompanying table titled “STATUS well. OF MAJOR MAINTENANCE The mowing and debris pick-up work PROJECTS.” Multi-purpose Projects was done on 270 different sections of In 2005 we again joined forces with urban native-grass-lined drainageways It used to be that when the last piece of other local governments to fund multi- within the District's boundaries. The construction equipment left the work purpose projects. Drainageways and contractual value of the work was site the project was finished. Permit parks often share the same corridor. $657,770. The table below summarizes regulations now often require that the Dave Bennetts, Senior Project Engineer, the miles of drainageways within each revegetation of a completed project be coordinated with staff from Denver county in the District on which we monitored and documented for several Parks to design improvements to West performed regularly scheduled mowing years. The goal is to ensure that Harvard Gulch at Clay Street, West and/or debris pickup maintenance. vegetation and habitat are restored to Harvard Gulch at the South Platte pre-construction levels. These annual River, and Sanderson Gulch at Florida Routine Maintenance Summary for site inspections and reports require our Avenue. Each site had unique hydraulic 2005 on-going attention plus the services of and right-of-way problems and different Adams County 20.9 miles qualified vegetation specialists. residential/recreational needs. Arapahoe County 39.7 miles Sanderson Gulch is now under Boulder County 17.6 miles Channel Repairs construction and is being administered Broomfield County 0.2 miles In last year's Flood Hazard News we in the field by Mike Sarmento, Senior Denver County 44.4 miles described a project on Grange Hall Construction Manager. Douglas County 11.4 miles Creek between Grant Street and I-25 in Jefferson County 30.4 miles the City of Northglenn. Some Two projects in Lakewood made use of TOTAL 164.5 miles improvements had been constructed in combined funding to repair severe the past, but they were deteriorating. A erosion to residential backyards.

10 Stacked boulders were used to limit the STATUS OF MAJOR MAINTENANCE PROJECTS channel width and still maintain the flow capacity of McIntyre Gulch west Project Jurisdiction Cost Status of Holland Street. Boulders and riprap ADAMS COUNTY th were used to make repairs to Lena Grange Hall Creek – 108 Av. to Colorado Thornton Design 4,280 100% Remove substantial sediment buildup Const 61,226 100% Gulch east of Youngfield where the Grange Hall Creek – Grant St. to I-25 Northglenn Design 86,387 100% contractor had to deal with difficult Build small drops and repair channel Const 398,810 100% access conditions. On both projects the Niver Creek – York St. at Coronado Pkwy Adams County Design 18,345 80% City of Lakewood managed easement Remove sediment and repair pipe outfalls Const next year 0% acquisition in addition to participating in ARAPAHOE COUNTY the project funding. Coon Creek – West of Platte Canyon Road Arapahoe County Design 44,459 100% Local channel and bank repair Const 139,676 100% Multi-purpose projects occasionally take Little Dry Creek – East of Colorado Blvd Centennial Design 57,963 90% Local small drops and channel repair us into irrigated bluegrass parks. In Const next year 0% Broomfield we used wrapped soil lifts Little Dry Creek – Orchard & Brook Val Centennial Design 40,362 100% Repair vertical bank & rebuild channel Const 98,015 100% reinforced with vegetation to provide Willow Creek, Foxhills – S of Dry Ck Rd Centennial Design In-house 100% low flow bank protection on City Park Rebuild drops and repair channel Const 216,963 100% Drainageway south of Midway Willow Creek, Kettle Tr – W. of Yosemite Centennial Design In-house 100% Boulevard. Since we were in an Rebuild pipe outlet and repair channel Const 116,330 100% improved park a narrow concrete "mow BOULDER COUNTY strip" was installed behind the upper soil Boulder Crk – West of 9th St, Eben Fine Pk Boulder Design In-house 100% lift to provide an edge for the bluegrass Rebuild river rock drops, repair erosion Const 108,026 100% and a solid surface for mower wheels. Dry Creek #2 – N.E. of 55th St. & Arap. Boulder Design 82,204 100% Replace 3 broad drop structures Const 338,161 5% Detention Ponds and Sediment Rock Creek – Farm west of Hwy. #287 Boulder County Design 76,178 100% Control Channel repair, drops, trails, and plants w/Boulder Co Const 681,835 100% BROOMFIELD COUNTY The hydraulic designs of urban City Park D'way – Emerald to Midway Broomfield Design 70,769 100% drainageways are generally intolerant to Channel and bank repair Const 293,298 100% sedimentation and aggradation. A DENVER COUNTY change in bottom elevation of just a foot Cherry Creek – U/s & d/s of 11th & Speer Denver Design 11,013 100% can have a dramatic impact on the flow Soil lifts and plants to protect low flow Const 105,708 100% characteristics and the associated Goldsmith Gulch – Iliff to Yale at Monaco Denver Design 69,130 60% floodplain of an urban grass-lined Repair channel, trash rack and det. pond Const next year 0% stream. Concrete-lined channels can be Montbello Channels – N.E. of I-70&Peoria Denver Design Previous 100% even more sensitive to aggradation Ongoing replacement of concrete channel Const 167,084 100% where even a couple inches of sediment Sanderson Gulch – At Florida Avenue Denver Design 100,138 100% is visible and can support undesirable Repair banks and add & repair drops Const 775,000 100% vegetation. In the past year the West Harvard Gulch – Platte R to Railroad Denver Design 149,413 90% Drops, channel repair, and trails with Denver maintenance Program carried out Const 857,377 0% significant sediment removals on West Harvard Gulch – Zuni St. to Clay St. Denver Design 176,268 100% Corridor study, drops, channel repair with Denver Const 572,000 0% Grange Hall Creek in Thornton from th DOUGLAS COUNTY 108 Avenue to Colorado Boulevard, Big Dry Ck, Wildcat Trib – W of Quebec Douglas County Design 14,299 50% and at the sediment trap on Willow Sediment removal & design sed. trap Const 21,144 10% Creek south of Dry Creek Road in Happy Canyon Ck – At Oak Hills Drive Douglas County Design 44,334 100% Centennial. Add a drop to protect upstream drop Const 196,945 100% Sulphur Gulch – SE Main & Stonehenge Parker Design 23,960 100% We have removed sediment several Add 2 more drops to stabilize channel Const 173,625 100% times from the low flow channel of an JEFFERSON COUNTY on-stream detention pond on Wildcat Coon Creek – S.E. of Bowles and Jay Ct Jefferson County Design 51,310 100% Ridge Tributary to Big Dry Creek in Drops and repair channel & water line partic. Const 246,790 100% w/Den.Water Douglas County. We are assessing the th Lena Gulch – From 20 Av to Youngfield Lakewood Design 50,300 100% upstream sediment sources to determine Drops and repair channel w/Lakewood Const 210,000 100% if we should construct a sediment trap Little Dry Creek – Hoyt/Kipling, N of 80th Arvada Design 56,580 100% which would make maintenance much Drops and channel repair Const 192,680 100% easier. McIntyre Gulch – West of Holland St. Lakewood Design 76,800 100% Repair eroded channel banks w/Lakewood Const 474,000 100% th Making changes to drainageway Tucker Gulch – Ford St. at 7 Place Golden Design 23,400 40% Repair narrow urban channel Const next year 0% configurations in urban areas is often a balancing act. Flowing water has a mind of its own and if you try to confine

11 it too much in one area it may respond shifted enough that water now flows by popping out in a nearby area. An through the structures and has caused an off-channel detention pond was undesirable combination of constructed for Goldsmith Gulch at sedimentation and erosion. Our project Iliff Avenue in Denver several years will rebuild the drop structures to ago. The pond is immediately upstream restore the water table, reduce the of a long box culvert that goes under a sediment deposition, and better manage shopping center parking lot. Each the low flows and stormwater flows. runoff event brings with it its own set of stream flow characteristics. Ideally, flow in the box culvert will be maximized before stormwater starts spilling into the detention pond. Also, the detention pond should fill with water before any flow overtops the box culvert and flows through the parking lot. Goldsmith Gulch has often disregarded this logic and as a result we are participating in a study to reconfigure these sensitive elements of the drainageway.

Drop Structures Last year we mentioned that drop structures can fail when water flows through, under, or around them due to an inadequate cutoff wall. Drop structures can also be damaged in another way. When the channel bottom downstream from a drop is steeper than its equilibrium slope nature will try to th flatten the slope by eroding upstream. If Lena Gulch in Lakewood between 20 Avenue and Youngfield Street. Boulder enough elevation is available for the edge channel built within a confined backyard drainagewayeasement stream the erosion can eventually undermine the foundation of a drop structure. In the Town of Parker we added two drop structures on Sulphur Gulch south of Main Street to flatten the longitudinal slope and reduce the threat to a recently built sculpted concrete drop structure. A similar structure was built on Happy Canyon Creek at Oak Hills Drive in Douglas County to stop erosion that was undermining the energy dissipation basin of a drop structure built several years ago. The close coordination of multiple interests on both projects was guided by Cindy Thrush, Senior Project Engineer. Jeff Fisher, Senior Construction Manager kept all the parties informed and coordinated while overseeing the construction.

A large stand of cattails and other wetland plants exists on Dry Creek No.2 east of 55th Street in Boulder. This th environment was created by three wide Little Dry Creek north of 80 Avenue in Arvada. This grouted boulder drop drop structures made up of large stacked structure has stabilized the channel within the park and protects a sanitary sewer concrete blocks. These blocks have line that had been completely exposed by erosion.

12 ALERT Webserver Enhancements By Chad Kudym, Project Engineer, Information Systems and Flood Warning Program

In Spring of 2005 the District’s ALERT webserver http://alert.udfcd.org was updated with GIS-based mapping of topography, hydrography, roads and ALERT gages, as well as drill-down capabilities that enhance data access. This update helps users visualize features that influence flood threats and facilitates quick access to a variety of displays.

The map illustrates the utility of the updated ALERT webserver for the June 3, 2005 storm. This is the default image displayed when a user requests a map. Although no rainfall amounts are shown, it does provide a very clear snapshot of current 1-hour rainfall activity for the entire ALERT network. The map automatically updates every five minutes if no browser activity is sensed. The map includes a shaded relief topography map, county Clicking on the rainfall readout late November we switched boundaries, major highways, major associated with the station will launch a communications from a dedicated ISDN streams and water bodies, and the separate browser window with a table of connection to a high speed T-1 line. We District boundary as background the last 100 data reports for the gage. trust that this will be another welcomed features to assist with data assessment. The data table lists the date/time of the change, but we are not done yet. White dots indicate rainfall activity with bucket tip along with corresponding Currently we are working on PDA- less than one inch falling in the past cumulative precipitation totals since the friendly webpages that will allow hour. Yellow dots highlight rainfall data transmitter was last reset. The convenient wireless access to many activity reflecting one to three inches of table also lists a “raw” data value that useful, easy to interpret displays. rain, and red dots warn of rainfall reveals missing bucket tips and a greater than three inches for the same 1- column that indicates when alarm hour time period. Tabs along the thresholds are exceeded. Other bottom of the map provide a dashboard summary tables that list daily amounts of options for accessing critical and storm totals can be obtained from information related to weather and links provided in the left frame of the flood-related threats. map window.

At 4:55pm, the yellow dot near I-25 and All maps include browser navigation Hampden indicates that localized that not only allows you to quickly drill- flooding may be occurring that deserves down to more detailed maps, but also to a closer look. The user can click on the move to adjacent maps. The streamflow map where the highlighted dot is located maps function very similarly to rainfall and the browser will display a more maps and use the same background detailed map showing the location of the images. Useful weather maps are also gage with the total rainfall amount available. The District wants to measured for the past hour. More encourage local agencies to use this detailed maps can be viewed by clicking website to develop a level of comfort on each subsequent map until the with the tools that are available. Of desired scale is found or the best course, any feedback you have is always available map is finally reached. The welcome. user can then hover the mouse pointer over the gage of interest and a popup Another more recent enhancement that will appear showing the station name Internet users will start noticing is the and the gage ID number. substantially improved speed at which these webpages are now rendered. In 13 Maintenance Eligibility Program Notes By David Mallory, P.E., Senior Project Engineer, Floodplain Management Program

Construction Plan Reviews impacts to waters of the United States In the field We continued to see a large number of and associated wetlands. However, not One of the truly rewarding and construction plan submittals again this all projects follow the preservation enlightening aspects of my position is year. The eastern E-470 and northern I- model. The District/ACOE field operations. I see a lot of projects 25 corridors have attracted the largest coordination helps to facilitate and over the course of a year and some stand development interest for both streamline the approval process. The out in terms of design and construction commercial and residential other essential partner is of course local execution. One project I’d like to share development. Providing timely reviews government. Throughout the year we is the Parker Auto Plaza. As the name is always challenging and this year was have moved towards larger implies, the project is located in the no exception. Terri Fead, PE, CFM has representation at project meetings with Town of Parker, along Baldwin Gulch, supplemented District staff throughout positive results. approximately 2,000 feet from South the year. Terri’s involvement has been Parker Road to Twenty Mile Road. The a tremendous benefit to the Maintenance Private land development projects are Town of Parker has committed to using Eligibility Program and I'm happy to responsible for constructing perhaps sculptured concrete drop structures after announce she will be part of the one-half to two-thirds of the Denver very successful public projects along program again next year. The District’s metropolitan area's major drainageway Sulphur and Tallman Gulches (in maintenance eligibility database, infrastructure. In working with local cooperation with the District’s Design updated bi-monthly, and the Guidelines governments, developers and their and Construction, and Maintenance for Maintenance Eligibility Of Flood consultants, we have also been mindful Programs). Baldwin Gulch was Control Facilities Constructed By that major drainageways must be realigned and stabilized with four, five- Others (Maintenance Eligibility attractive, provide a community asset foot, 100-year capacity sculpted Guidelines) have been available online and represent a "sense of place" in concrete drop structures. Kiowa throughout the year. addition to functioning hydraulically. Engineering Corporation was retained to Michelle Leach and I presented papers produce the construction plans. This The District and Army Corps of on this subject at the District’s April was the first sculpted concrete drop Engineers (ACOE) have made a workshop and CASFM’s annual project approved through the District’s concerted effort to coordinate our conference in September. Many Maintenance Eligibility Program. I took maintenance eligibility and the ACOE's projects require floodplain revisions a lot of pot shoots at the “natural” drop Section 404 permit programs. To that through the Federal Emergency structures in the “natural” engineered end we are encouraging joint meetings Management Agency's letter of map channel, next to the “natural” auto and site visits. While these programs revision (LOMR) process. We spend a dealership as opposed to our previously have different goals and purposes; there lot of time mentoring development stated preservation preference. are definitely shared objectives. The applicants and their consultants in However, the design included several District has long promoted preservation preparation of LOMRs for development effective components, which made all of floodplains, which also avoids projects. the difference as I’ll discuss below.

Concrete placement on April 8, 2005, for the largest of the Matt Erichsen with Kiowa Engineering Corporation and sculpted concrete drops started at 7:00 am and was Chris Castelli with Farnsworth Group (center foreground) completed in the late afternoon. The entire workforce of provided interactive construction observation. The final Naranjo Civil Constructors was involved. This brings new surface treatment cannot be completely conveyed through meaning to the term, teamwork. design drawings, rather through skilled field control and a willing contractor.

14 The Town of Parker and the District agreed to involve the Farnsworth Group in the construction observation of the sculpted drops, based on their previous performance with the Sulphur Gulch project. Another veteran of the Sulphur Gulch Project was Naranjo Civil Constructors. They were again contracted (through a subcontractor arrangement with the site general contractor) to build the channel improvements. Kiowa Engineering Corporation was retained to provide construction observation for the remaining channel improvements. All consultant and construction costs were born by the developer, as is customary in Parker. Several other subcontractors were hired for the Twenty Mile Road View from the top of the completed drop towards the Twenty Mile Road crossing. culvert crossing. Note the grouted boulder transition and open three-sided concrete box culvert section. Concrete placement for sculpted drops is unique. The drop structure featured in the accompanying pictures required 230 cubic yards of concrete. The Naranjo placement team numbered 25 and required a lot of teamwork. Field engineers from both Farnsworth and Kiowa were present for the entire pour. Concrete delivery proved to be the critical path and stretched the placement time for this largest and final drop to 8 hours. A similar grouted sloping boulder drop would have resulted in half the quantity of grout and placement time. Therefore, cold or hot weather placement could become a significant factor with sculpted drops. An overhead power line through the middle of this View of the completed project looking upstream from Twenty Mile Road. site necessitated the use of two concrete The large drop structure is in the immediate foreground. The extended pumper trucks, and each pumper crew approach section is for underground utility protection. The mature included the operator, a power line cottonwood trees identify the preserved oxbow location. spotter and supervisor. Concrete delivery was staged at two locations and span, three-sided concrete box culvert channel, but within the 100-year included supervisors and quality control with a pedestrian trail and grouted floodplain and receives sustaining water personnel in addition to truck drivers. boulder low flow channel. Notice in the from storm sewer outlets. The general contractor sent a delegation included picture how open the section to observe the concrete placement, as is, allowing continuous sheet flow from My compliments to everyone involved did the Town of Parker. Altogether I the trail to the low flow channel. The in the Parker Auto Plaza for creating a counted 50 people on site. Obviously, a benefits in terms of increased light, channelization project that sets the bar lot of expertise, coordination and safety and appearance, and reduced for excellence in future major teamwork are required to successfully maintenance are obvious. Another drainageway projects. execute a sculpted drop design. We are important feature in overall corridor told the sculpted concrete drops are experience is landscape design. I think similar in cost to comparable grouted thoughtful and skilled surface sloping boulder drops. restoration is essential to the overall project success. And finally, the design Several other features of this project are consultant team was able to preserve worth noting. First, the Twenty Mile one of the pre-project stream oxbows. It Road crossing was designed as a single- is outside of the realigned low flow

15 Flood Warning Program Notes By Kevin G. Stewart, P.E., Manager, Information Services and Flood Warning Program Introduction to devote the remainder of this column flood hazards and very soon, the second This year brought a number of to the headline: In the Aftermath of phase for Boulder will be underway. interesting changes to the District. As Katrina. Project funding to date has been noted in the Executive Director’s provided by the District, Boulder, column, our information services and The gulf coast hurricane disasters Jefferson County, the Colorado Water flood warning (IS/FW) activities were continue to be a hot topic for headline Conservation Board, University of elevated to full program status and we news and magazines across the Country. Colorado, U.S. Geological Survey, doubled our full-time staff to a grand The catastrophic flood losses and death FEMA through the Colorado Office of total of two with the addition of Chad toll have caused many communities to Emergency Management, and the Public Kudym. Derrick Schauer helps us out ask the question—could this happen Entity Risk Institute. The multimedia as our part-time IT consultant and here? Dave Lloyd answered this very website features flood videos, Stephanie LaCrue assists us in-between well in his column and yes, we are very testimonials, descriptions of past floods, her studies at the Colorado School of fortunate to live in Colorado, but we aerial photographs, flood inundation Mines and helping Mark Hunter with should never forget our flood history as maps and a media kit for use by local the District’s Maintenance Program. current events remind us of how newspapers and TV stations. More What a team! vulnerable we really are. community involvement is planned for Boulder’s second phase as well as a IS/FW activities are not new for the District communities prepare for the feature length video production for District, but both are heavily driven by inevitable possible PBS broadcast. information technology. Consequently, As our nation deals with the recent gulf our system support requirements have coast catastrophe, the elevated fear Is my property in or near a steadily increased and the need to adapt factor has caused District communities floodplain? to new technologies never ends. One of to reevaluate their current capabilities, This frequently asked question has our main program objectives is to keep identify weaknesses and take prudent motivated the District to develop more pace with our local governments, steps to become more disaster-resilient. effective ways to help people find the consultants and other partners while The City of Boulder and University of answer. With the Internet being the striving to meet the demands of a Colorado at Boulder are currently vehicle of choice, we wanted to keep the modern office and an electronically developing comprehensive disaster procedure as open as possible, minimize informed public. Another growing need mitigation assistance plans. Once our system support requirements, avoid is to provide our Floodplain completed, FEMA will regard Boulder costly software acquisitions, and Management Program with GIS and IT and CU as a disaster resistant leverage available Internet resources. support for FEMA map revisions and community/university. This designation Bruce Rindahl with Leonard Rice DFIRM conversions (see Bill DeGroot’s will qualify them for federal mitigation Engineers (LRE) developed a procedure column). Other District programs also funding to further reduce their risks. for the District that utilizes an open utilize GIS and require periodic staff These plans are intended to address all source Internet program language training and assistance. hazards, but the flood risk is considered known as Scalable Vector Graphics their primary threat. (SVG). The address locator is powered Over the past two decades we have by Google. The USGS and Microsoft’s accumulated a sizable archive of Denver is also focusing on improving Terraserver are the source for electronic information. Better flood response capabilities by background images. GIS shape files are strategies, procedures and facilities are undertaking a detailed review and used to render transparent floodplain needed to effectively manage and update of their standard operating overlays, roads, hydrography, county protect these resources. IT procedures. Efforts are also underway boundaries and the District boundary. infrastructure improvements will be in to prepare a comprehensive flood LRE is hosting the website. An SVG place early next year to help us meet recovery assistance plan. AMEC is demonstration webpage link can be this challenge. providing consulting services for found on the District’s homepage Denver and the Boulder/CU projects. www.udfcd.org. The IS/FW program is also responsible The District is participating in these for documenting floods that impact the activities. CoCoRaHS update District. This activity turned out to be The District has been a CoCoRaHS one of our lesser chores this past year. Flood safety information online sponsor since 2002. CoCoRaHS stands In fact, the 2005 flood season may be The flood safety information website for Community Collaborative Rain, Hail considered one of the District’s least http://floodsafety.com/colorado project and Snow Network. It was started by active in its 36-year history. In spite of was started in 2003 as a cooperative the Colorado Climate Center at this reprieve, the interest in local flood effort between the District and the City Colorado State University following the response and recovery has never been of Boulder. The project was later 1997 Fort Collins flood. Nolan higher. It is so high that I was tempted expanded to address Jefferson County Doesken heads this nationally

16 recognized project that includes project can be found at governments from April 15 through cooperative observers from neighboring www.udfcd.org/emwin. September 15. HDR Engineering of states. Anyone interested in becoming a Denver provided the operational support CoCoRaHS observer or learning more ALERT System News for 2005. John Henz was HDR’s about this program should visit their The District’s 173-station ALERT project manager and lead meteorologist. newly improved website system includes: This was the fifth consecutive year for www.cocorahs.org. 151 rain gages HDR as the District’s meteorological 84 stream gages services provider. 18 weather stations 7 repeaters 2005 District floods 6 base stations The 2005 flood season was the fourth 2 web servers consecutive year deemed below average with regard to the number of observed Five new stations experienced their first threat days, 22 compared to an average full year of operation in 2005: Aurora annual number of 28. No messages FS-12, Flying J, Murphy Creek, Shop were needed during the months of April, Creek and Iliff Pond. The first 3 May and September, which is quite stations are located in the Upper Sand unusual. June 2-3 kicked-off the flood Creek basin in Aurora. The Shop Creek season with flash flood warnings being rain gage is a relocated site near Quincy issued for both days. Following this Ave. and Parker Road in Aurora. The two-day threat period, subsequent previous Shop Creek station was storms produced only minor nuisance CoCoRaHS/ALERT web display installed in 1990. The Iliff Pond station flooding with the threat remaining low is located on Goldsmith Gulch in until August. Flash flood watches were LRE used SVG to develop an improved Denver. issued for August 3 and 10. July was CoCoRaHS/ALERT combined data abnormally hot and dry with few display for the District. The interface is The newest station to come on line is thunderstorms. Only four July days had identical to the floodplain mapping the Stapleton weather station, which any real flood potential, of which three procedure described previously and can was formerly located at the Urban Farm received some street flooding rains. The be run from the same website. Real- and discontinued in 2003. The new site late arrival of the Arizona monsoon time data is accessed directly from is just east of the old site near Havana (July 18) was identified by HDR has the XML files generated by the two source and Smith Road. reason for the odd July weather. Their websites. Rainfall for the previous day report also notes that this was the is then rendered for the browser. The By spring of 2006, we are anticipating second latest appearance of the application also includes an historic data four additional stations: two on Boulder monsoon in the past 50 years and that retrieval feature. A free plugin from Creek in the City of Boulder, one on the Colorado monsoon season did not Adobe is required for Internet Explorer Lakewood Gulch in Denver and another begin until August. In looking back at users. The latest version of Mozilla near the Colfax Ave. crossing of Sand Colorado’s flood history, the last week Firefox does not require a plugin. Creek in Aurora. New system in July through the first week in August expansion projects are anticipated for has been a notoriously deadly flash EMWIN-Denver update Aurora, Parker and Douglas County, flood period. Once again, the District EMWIN is a National Weather Service and the District is investigating the was fortunate to make it through another satellite downlink/rebroadcast system possibility of installing an ALERT rain year relatively unscathed. that stands for Emergency Managers gage at NCAR’s precipitation Weather Information Network. It measurement test site located south of Days with Flood Potential allows communities to develop their Boulder near Marshall. OneRain of June 2-3,9-10,12,16,20-21,23-25 11 own unique applications including civil Longmont provided the 2005 ALERT emergency messaging. This low-cost maintenance services for the 14th July 4,15,24-25 4 system is being activated this month and consecutive year. August 3-5,9-11,16,21-23 10 was made possible by a partnership between local emergency managers, the Our Internet website has been improved District, the NWS and Xcel Energy. substantially this year. Be sure to read The following briefly describes the Skywarn Systems, Inc. of Fort Worth, Chad Kudym’s article to learn the more notable rainfall events of 2005: Texas is the project consultant. DHS details. grant monies were used to acquire 31 Thursday, June 2 EMWIN receiver systems. Additional Meteorological Support This was the first message day of the DHS funds have already been approved The District’s 27-year-old flash flood year for the F2P2. A localized intense for expanding the radio coverage next prediction program (a.k.a. F2P2) thunderstorm over DIA dropped copious year. More information about this provides daily forecasts and flood threat amounts of pea-size hail, clogging inlets notifications to District local and causing street flooding along Pena

17 triggered nine ALERT rainfall 2005 Peak Flows alarms from Date/ Location Peak cfs measurements that Time Depth ft. approached 1.5- inches in less than June 3 Harvard Gulch at Jackson 410 30 minutes. From 17:01 Street Depth 3.1 a statewide June 3 Slaughterhouse Gulch at 88 perspective, the 17:07 Grant Street Depth 6.8 rainfall activity June 3 Goldsmith Gulch at 450 was particularly 17:11 DTC/Temple Pond Depth 6.9 noteworthy with June 3 Goldsmith Gulch at 540 total amounts 17:11 Eastman Ave. Depth 3.5 exceeding 2-inches June 3 West Toll Gate Creek 440 in eastern 17:27 above Confluence Pond Depth 1.6 Colorado and more June 3 Goldsmith Gulch at TBD June 3 street flooding in southwest Aurora than 3-inches in Kansas and 17:32 Iliff Pond Depth 8.5 Nebraska. Based June 3 Confluence Pond on 940 Blvd. This storm prompted the NWS to 17:37 West Toll Gate Creek Depth 3.4 issue a flash flood warning. The eastern on CoCoRaHS data, the State Climate th plains received the more serious weather Office estimated that the volume of June 3 Sable Ditch at 18 Ave. 180 17:39 Depth 2.3 with softball-size hail reported near rainwater that fell on this day would be Limon. equivalent to one-third of an inch depth June 3 Horseshoe Park Drop on * 1910 of water over an area of 450,000 square 18:08 West Toll Gate Creek Depth 3.2 miles. That is one very impressive Friday, June 3 June 3 Powers Park on TBA This storm resulted in the District’s hydrologic event! 18:35 Slaughterhouse Gulch Depth 7.2 worst flooding of 2005, disrupting yet Wednesday/Thursday, August 3-4 June 3 Iliff Pond detention another Friday afternoon rush hour. 18:42 basin for Goldsmith Gulch Depth 6.1 This happens a lot! This time the A cold front accompanied by weak steering winds prompted the issuance of June 3 Utah Park on Westerly 177 heaviest rain fell in Denver and Aurora 18:52 Creek Depth 6.5 with storm totals approaching 2.5-inches a flash flood watch on the morning of August 3. Heavy rains arrived that June 3 Toll Gate Creek at 6th 730 over parts of lower Cherry Creek, 19:29 Depth 3.2 Goldsmith Gulch, Westerly Creek and afternoon with rainfall alarms occurring Toll Gate Creek. The majority of the in Brighton and at Red Garden in June 3 Cherry Creek at Champa 1950 rain fell within a 30 to 45-minute Eldorado Canyon State Park. The 19:33 Street Depth 5.5 Brighton weather station measured the period. The Littleton area was also June 3 Sand Creek at Mouth 2570 impacted by street flooding and large highest rain total of 1.50 inches. Less 19:33 GageHt 6.7 hail. The ALERT system reported 30 heavy rains continued overnight causing concern about possible stream and river June 3 Cherry Creek at Steele 1430 rainfall alarms between 4:30 and 6:30 20:15 Street Depth 2.9 flooding. By morning, rainfall amounts p.m. th were approaching 3-inches at some June 3 Granby Ditch at 6 Ave. 38 20:17 Depth 6.3 The Horseshoe Park stream gage on locations and streams like Cherry Creek and the South Platte River were running Aug 4 South Platter River at 3rd 2820 West Toll Gate Creek set a new high 05:49 Ave. GageHt 4.1 water record with a peak flow of 1,900 high. cfs just after 6 p.m. Goldsmith Gulch Aug 4 South Platte River at 19th 5510 06:07 Street GageHt 8.3 overtopped Iliff Avenue in Denver The events described above represent while the side-channel detention basin at the most interesting storm days of 2005. Aug 4 Kelly Road Dam on 82 that location filled to a depth of 6.1 feet. Heavy rainfall capable of causing minor 15:35 Westerly Creek Depth 10.3 flooding was verified by HDR for 17 Residential flooding in Denver’s Aug 4 Englewood Dam on 160 Hampden Heights East subdivision was additional days: June 9, 10, 12, 16, 20, 16:25 Willow Creek Depth 19.6 the subject of many follow-up news 21, 23, 24; July 15, 24, 25; and August 9, 10, 11, 16, 21, 22. More information Aug 4 South Platte River at 5670 reports. 18:53 Henderson GageHt 8.4 about the 2005 flood season and * New Record Monday, July 25 ALERT system operations can be obtained by reading the HDR The heaviest rainfall this day missed the District, but hit the ALERT gages in the Engineering and OneRain annual Jamestown area of Boulder County reports. Links to these documents and between 4 and 5 p.m., causing a return other useful material can be found on of mudslides in the burn area impacted the bulletin board webpage at by the 2003 Overland Fire. The storm alert.udfcd.org.

18 District Project wins CASFM Honor Award David Bennetts, P.E., Senior Project Engineer, Maintenance Program

A project jointly sponsored by the District and the City of Denver won a CASFM Honor award at the 16th Annual Colorado Association of Stormwater and Floodplain Managers (CASFM) conference held in Steamboat Springs in September. A brief description of the project is given below.

The Hutchinson Park and Goldsmith Gulch Channel Improvements was a joint project sponsored by the Denver Parks Department and the District's Maintenance Program. Construction of the project was completed in late summer of 2004. The 17.5-acre project site has a large wetland area with a formal park on one side and a boardwalk trail along the drainageway. The wetland was starting to degrade due Faux rock drop structure sculpted to resemble rock outcropping. to channel incising, which was lowering the water surface. Drop structures were center pier design. Ironwood, known needed to repair the degraded channel for its 50-year lifespan, was used for and elevate the water surface back up to decking; and Alaskan Cedar was used to its original elevation. The Parks develop the curved alignment and Department wanted to upgrade the trail enhance the edges of the boardwalk. It system in the park and connect it to the also provided an element of safety, regional trail as well as improve the while concealing the foundation. playground and install new equipment.

The $1.2 million project included construction of faux rock drop structures providing a place to sit next to the water; channel stabilization and rehabilitation; installation of a recycled pedestrian bridge salvaged from another District project, providing the opportunity to view wetlands and wildlife; an upgraded trail system connecting to the regional trail; and irrigation and playground improvements. The project also removed several condominium buildings from the floodplain. Although they were not in the official floodplain, hydraulic modeling for the project showed them to be. The “floating bridge” over the water quality pond. One unique feature of this project was the construction of a water quality pond to capture and treat stormwater runoff from a large parking area. Over the top of the water quality pond is a new boardwalk that appears to float over the wetland as if bridging the area without support. This was achieved through a

19 South Platte River Program Notes By Bryan Kohlenberg, P.E., Senior Project Engineer

Forty years ago, last June, I stood in the acquire lands within the South Platte contractors. These aerial photos were early evening hours with my dad atop River floodplain. converted to pdf format and posted on the McClellan Reservoir Dam, just east our web site (www.udfcd.org) to of Santa Fe Drive at County Line Road. Zuni/Sun Valley Reach Project provide local governments and other Earlier that day, he had been advised to Unfortunately for this project, Congress agencies with the ability to download leave work at Martin-Marietta and has again failed to enact the Water them. return home across the South Platte Resources Development Act (WRDA), River prior to the arrival of a massive which includes $18.9 million for this Noxious Weed Management "wall of water" moving down Plum project. Even though it is doubtful that We continue to be aggressive in Creek toward the river. Sure enough, this project will receive Federal funding controlling the many varieties of the valley below us filled quickly with any time soon, Denver and the District invasive vegetation that have taken hold floodwaters and debris that soon raced are committed to implementing this along the River. This vegetation towards Denver devastating everything project. includes both noxious weeds and in its way. It was not until several days noxious trees. We continue to assist later we learned that the "Flood of In 2005 the U. S. Army Corps of local governments in the control of such 1965" had taken 21 lives and caused Engineers, Denver and the District were weeds as Purple Loosestrife, Thistle $540 million in damage. able to pull together enough funding to (various species), Knapweed and other move the final design of this species. Our Senior Construction It was this flood that inspired the environmental enhancement project Manager, Steve Materkowski, was creation of the District and ultimately slightly forward. This work allowed invited to speak to several youth groups, led to the formation of the South Platte Denver to start actively pursuing real including Earth Force, regarding the River Program in 1987. In my mind, estate and utility relocation needs along District’s efforts in controlling noxious however, the Program began in June of this reach of the South Platte River weeds and habitat rehabilitation. 1965. Now that I have been given the between 8th Avenue and Lower Colfax responsibility of managing the South Avenue. Working closely with local Platte River Program I feel fortunate to governments, we have removed have seen the flood event that started it Maintenance Activities Tamarisk (a.k.a. salt cedar), Russian all. Today the Program consists of Routine Maintenance Olive, Chinese Elm and a variety of myself as Senior Project Engineer and In 2005, South Platte River routine noxious weeds through cutting, and Steve Materkowski as Senior maintenance efforts included: selective and careful application of Construction Manager. Next year we • 192 river miles (equivalent) of trash herbicides, when needed. This is will have the services of a student intern and debris pickup and removal followed by the plantings of native to assist with routine maintenance • 3.6 acres of string-trim mowing at Plains Cottonwood, Willow, shrubs and inspections. access ramps and rest areas various native dry land grasses. • 78 miles (equivalent) of Capital Projects recreation/maintenance trail edge This year undesirable trees have met Globeville Phase 3 Project mowing their match with the addition of a new The construction phase of Denver’s • 9.1 miles of tree pruning along the piece of equipment to the CTM lineup. project to remove approximately 200 trail The "Tree Shear" is a piece of tractor- mounted equipment that allows the acres of highly urbanized lands in north • Removal of dead trees and other operator to hold the tree while hydraulic Denver from the 100-year floodplain is large items from the river shears cut the tree near ground level underway. Lawrence Construction was • Participation in annual NIMBY (See photo 1). The tractor can then awarded the project based upon ("Not In My Backyard") FEST move the cut tree to a staging area or interviews and cost proposals. Under volunteer trash cleanup event directly to the chipper. By using this agreement to the District, Love and equipment, our contractor is able to Associates and their sub-consultants are This year over $260,000 was spent to remove more trees in less time than providing construction management perform these services along the 41 traditional methods allow. As always, services for Denver. Construction is miles of river between C-470 and the herbicide, with dye, is immediately scheduled to last 810 days and should Adams/Weld County Line. Colorado applied to the cut stump. be complete in the late winter of 2008. Total Maintenance (CTM), Inc. was

hired once again to perform these Our efforts in Denver and Arapahoe Floodplain Acquisition services. Counties have significantly reduced the The District continues to look for The 2005 routine maintenance contract quantity of Tamarisk adjacent to the opportunities to partner with Adams utilized color aerial photos of the river South Platte River. These plants are County and other jurisdictions to corridor in GIS format. This provided more detail and better annotation for our 20 found either individually or in small • Repair of failing riprap revetment Next year we hope to have the stands scattered throughout the river toe at two locations within the Army following cooperative projects Corps of Engineer's channelized section constructed: corridor. In Adams County, we between Coal Mine Road and Hampden • Henderson Reservoir - East continue to find, control and eliminate Avenue along Englewood Golf Course riverbank restoration/stabilization on significant populations of Tamarisk. and the east riverbank 1200 feet property owned by Aggregate Industries We also continued working with the upstream of Oxford Avenue. just north of 104th Avenue Northeast Colorado Tamarisk Task • Repair of several riverbank • Stagecoach Stop Pit - East Force (NoCoTTF). For more stabilization and wildlife habitat riverbank restoration/stabilization on information about the NoCoTTF or rehabilitation structures within South property owned by LaFarge Inc. north effective Tamarisk control measures, Platte Park in Littleton. of 124th Avenue contact Kelly Uhing, Adams County • Construction of 1000 feet of east • Worthing Pit - East riverbank Weed Specialist, at (303) 637-8115 or riverbank restoration/stabilization restoration/stabilization on property [email protected]. adjacent to the new Ken Mitchell Lakes owned by Henderson Aggregates Inc. facility currently being constructed by (Albert Frei and Sons) just south of Restoration Maintenance the City of Brighton. This project is in 132nd Avenue In 2005, the following restoration response to on-going lateral river maintenance projects were completed: migration that threatens to bypass the • Construction of a new Brighton Ditch diversion structure. recreation/maintenance trail underpass at 104th Avenue by L&M Enterprises, Cooperative Projects with Private jointly funded by Adams County (See Property Owners photo 2). Cooperative projects are constructed on • Removal of artificial levee adjacent flowage and maintenance access to an old mining operation downstream easements dedicated to the District by of 74th Avenue in Adams County. This private property owners adjacent to the removal effectively reconnected the river in exchange for river restoration floodplain overbank to the main work. This year we obtained an channel. Excavation from the levee additional 73 acres of easement area. Photo 1: The "Tree Shear" removal was used to re-contour the lake To date over 730 acres of such bank and to create adjacent wetlands easements have been dedicated, and cottonwood gallery. resulting in over 31 bank stabilization • Replacement of the old wooden and/or river grade controls and riparian pedestrian bridge near 1st Avenue revegetation projects since 1987. (extended) in Denver (See photo 3). Several of these easements now contain The new 10-feet wide steel bridge, the river recreation trail, which doubles visible from Interstate 25, now as river maintenance access. incorporates a modified bridge approach ramp that is ADA compliant. This One new cooperative project was bridge represents the last of six wooden completed this year. Narano Civil bridges along the river trail replaced in Constructors constructed an additional th Photo 2: Newly completed 104 the last 12 years. 1000 feet of buried riprap bank Avenue Trail Underpass restoration/stabilization along the west • Replaced severely cracked or heaved concrete recreation/maintenance bank approximately 1300 feet upstream trail sections in Denver. of 104th Avenue. Aggregate Industries dedicated the easement upon which this Several restorative maintenance projects project was built. The project will help that are now being constructed or will keep the river from migrating into the be next year include: adjoining future water storage facility. • Restoration and stabilization of Currently the west bank of the river at 1100 feet of highly erosive west the McIntosh Farm Company south of riverbank near 164th Avenue extended 120th Avenue is under construction. in Brighton. Left Hand Excavating is installing buried riprap along the bank in order to Photo 3: New pedestrian bridge near • Lowering of the riverbank levee st and restoration/stabilization of the west help protect the over 100-year old dairy 1 Avenue (extended) in Denver riverbank at the new South Platte farm operations. The McIntosh's Fishing Lakes & Open Space just north dedicated 31 acres of riparian area in of 104th Avenue in Adams County. order to get District assistance along their property.

21

2005 Professional Activities of District Staff

Dave Lloyd, Executive Director *Chairman, Board of Advisors, Urban Watersheds Research Institute *Attended National Association of Flood and Stormwater Management Agencies (NAFSMA) 2005 annual meeting in Anchorage, AK in August. *Attended Colorado Association of Stormwater and Floodplain Managers (CASFM) 2005 annual meeting in Steamboat Springs in September *Member of American Public Works Association (APWA) and CASFM Bill DeGroot, Manager, Floodplain Management Program *Member of the Board of Directors and Chair of the Floodplain Management Committee of the National Association of Flood and Stormwater Management Agencies (NAFSMA). *Attended NAFSMA’s annual meeting in Anchorage, AK in August. Chaired the Floodplain Management Committee meeting, and gave a progress report to a plenary session. *Presented a paper on map modernization issues in a plenary session at the Association of State Floodplain Managers annual conference in Madison, WI in June. *Participated in a workshop entitled “FIRMS, What Every Community Needs to Know” at the annual meeting of the Colorado Association of Stormwater and Floodplain Managers in Steamboat Springs in September. *Member of NAFSMA’s working group on Multi-Hazard Map Modernization CTP Training. *Member of Association of State Floodplain Managers (ASFPM), American Society of Civil Engineers (ASCE), and Colorado Association of Stormwater and Floodplain Managers (CASFM). Kevin Stewart, Manager, Information Services and Flood Warning Program *Chairperson of the National Hydrologic Warning Council (NHWC) *Member of the U.S. Department of the Interior’s Advisory Committee on Water Information, Subcommittee on Hydrology *Member of Steering Committee for the American Meteorological Society’s Commission on the Weather and Climate Enterprise *Invited speaker at the New Mexico Floodplain Managers Association Spring Conference in Socorro, NM in May *Speaker & moderator at the Sixth NHWC National Conference and Exposition in Sacramento, CA in May *Attended Governor’s Annual Conference on Emergency Management in Breckenridge in August *Attended Annual CASFM Conference in Steamboat Springs in September *Member of ASCE, ASFPM, CASFM and the Colorado Emergency Managers Association Ben Urbonas, Manager, Master Planning & South Platte River Programs *Gave a talk at the District’s April 28th one-day seminar focused on porous pavements. *Continues to serve on the Board of Directors of the Cherry Creek Basin Water Quality Authority. *Serves on the Water Environment Research Foundation’s (WERF) Research Council. *Serves as Chairman on two of WERF’s Project Steering Committees for research projects on Quantification of Solids in Stormwater and the development of the International BMP Database. *Serves as Co-chair of WERF’s Project Steering Committee for research project on Impacts of Urbanization on Receiving Waters. *Served as a member of WERF’s Project Steering Committee for research project on Critical Assessment of BMPs. *Was one of the teachers at training workshops in June and July on EPA’s SWMM 5.0 Software and CUHP Interface, and was the lead instructor at a workshop on BMP Selection and Design in December. *Serves on the Water Environment Foundation’s (WEF’s) committee to update the Manual of Practice on Stormwater Management. *Serves on the program advisory committee for the Civil Engineering Department of Colorado State University. *Attended the National Association of Flood and Stormwater Management Agencies (NAFSMA) annual meeting and participated in its Stormwater Committee meetings in Anchorage, Alaska. *Co-authored, with John Doerfer, “Master planning for stream protection in urban watersheds,” Water Science and Technology, Vol. 51, No. 2, pp 239-247, IWA Publishing, London, England. Paul Hindman, Manager, Design and Construction Program *Co-Chair of Cherry Creek Stewardship Partners Annual Conference *Chair of the 2011 Denver Site Committee for the American Public Works Association (APWA) International Public Works Congress and Exposition. *Committee Member of National APWA Awards and Review Committee *Chapter Delegate, APWA Colorado Chapter Cindy Thrush, Senior Project Engineer, Maintenance Program *Co-authored and co-presented with ASCG Inc, on "Multi-Use Greenways with No Adverse Impact – Colorado Examples" at the 2005 Association of Sate Floodplain Managers Conference in Madison, Wisconsin. *Presented a paper "Monitoring Stream Restoration Projects, Why We Should Always Look Back" at the 16th Annual Colorado Association of Stormwater and Floodplain Managers Conference in September in Steamboat Springs.

22

Bryan Kohlenberg, Senior Project Engineer, South Platte River Program *Continued as NSPE’s scoring coordinator for the Jefferson Chapter and Colorado State MATHCOUNTS competitions for 7th and 8th graders. John Doerfer, Project Hydrologist, Master Planning Program *Chairman, Municipal Stormwater Workgroup, Colorado Stormwater Task Force. *Member, Impacted Water Supplies Advisory Committee, Colorado Water Quality Forum. *Member, Urban Water Resources Research Council, Environment and Water Resources Institute (EWRI), ASCE. *Member, Standards Committee - Management Practice for Control of Erosion and Sediment, EWRI/ASCE. *Member, Stormwater and Watershed Management Subscriber Committees, Water Environment Research Foundation. *Co-authored, with Ben Urbonas, “Master planning for stream protection in urban watersheds,” Water Science and Technology, Vol. 51, No. 2, pp 239-247, IWA Publishing, London, England. Mark Hunter, Manager , Maintenance Program *Co-Chairman, International Erosion Control Association (IECA) Stream Restoration Technology Section. *Member of IECA Technical Review Committee. *Member of IECA Awards Committee. *Committee member for the Mountain States Chapter of IECA. *Editor of newsletter for the Mountain States Chapter of IECA. *Member of Board of Directors and on the Operations Committee of the Metro Wastewater Reclamation District David Mallory, Senior Project Engineer, Floodplain Management Program *Co-presented with Michelle Leach "Sense of Place in Major Drainageway Design" at the UDFCD April Workshop. *Co-presented with Michelle Leach "Bridging the Gap Between Function and Beauty in Drainageway Design" at the 16th Annual CASFM Conference. *Attended the Second Annual Conference on Sustainable Urbanism. *Serves on CASFM's Board of Directors as Treasurer. *Member of CASFM and ASFPM. David Bennetts, Senior Project Engineer, Maintenance Program *Program Chair for the 16th Annual CASFM Conference in Steamboat Springs in September *Speaker at CASFM Conference in Steamboat Springs in September *Council Member, CU Denver Engineering Leadership Council *Committee Member, Urban Infrastructure Committee, CU Denver *Member of ASCE, APWA, and CASFM Ken McKenzie, Project Engineer, Design and Construction Program *Presented "Massey Draw Stream Stabilization / Water Quality Improvement Project" at the CASFM *Conference in Steamboat Springs in September. *Served on ASCE's Urban Water Resources Research Council. *Served on the Metropolitan State College of Denver Engineering Technology Advisory Board. *Served on the Board of Directors of the Urban Watershed Research Institute. *Taught courses on flood detention design and storm sewer design . *Member of ASCE and CASFM. Jeff Fisher, Senior Construction Manager, Maintenance Program *Co-Chairman for the annual Inspector's Conference for the Colorado Chapter of the American Public Works Association (APWA) in Denver, Colorado. Mike Sarmento, Senior Construction Manager, Maintenance Program *Received Applied Science Degree in Water Quality Management from Red Rocks Community College *Received certification as a Senior Engineering Technician in Heavy & Highway Construction from NICET *Received certification in Land Management and Erosion Control from NICET *Received certificate of completion for Water Quality Laboratory Analysis for Water and Wastewater Technology from Red Rocks Community College *Attended 2005 APWA Construction Inspector's Conference *Accepted award on behalf of the District for Purple Loosestrife Control from the Colorado Division of Wildlife Steve Materkowski, Senior Construction Manager, South Platte River Program *Graduated from the University of Colorado, Denver, with his B.S. in Civil Engineering *Spoke to various youth groups, including Earth Force, regarding various UDFCD activities including Noxious Weed Control and Habitat Restoration.

23 BOARD OF DIRECTORS DISTRICT STAFF

Executive Committee: Dave Lloyd, Executive Director W. Mike Maxwell, Chairman Floodplain Management Program Douglas County Bill DeGroot, Manager Karen Stuart, Chairman Pro-Tem David Mallory, Sr. Project Engineer City and County of Broomfield Information Systems and Flood Bart Miller, Secretary Warning Program City of Centennial Kevin Stewart, Manager Chad Kudym, Project Engineer Vacant, Treasurer Master Planning Program Noel Busck, Member Ben Urbonas, Manager City of Thornton John Doerfer, Project Hydrologist Members: Design & Construction Program Carol Boigon, City of Denver Paul Hindman, Manager How to reach us: Steve Burkholder, City of Lakewood Laura Kroeger, Project Engineer Ken Fellman, City of Arvada Ken MacKenzie; Project Engineer Phone: (303) 455-6277 B. H. Hoffmaster, Engineer member Peggy Lehmann, City of Denver Maintenance Program Fax: (303) 455-7880 Kathleen MacKenzie, City of Denver Mark Hunter, Manager Nancy McNally, City of Westminster E-mail: [email protected] Cindy Thrush, Sr. Project Engineer Andrew Moore, City of Erie Dave Bennetts, Sr. Project Engineer Web: www.udfcd.org Alice Nichol, Adams County Mike Sarmento, Sr. Construction Kathleen Novak, City of Northglenn Manager Art Patton, Engineer member Jeff Fisher, Sr. Construction Manager Susan Sandstrom, City of Aurora Will Tour, Boulder County South Platte River Program Color versions of all of the Guillermo (Bill) Vidal, City of Denver Frank Weddig, Arapahoe County Bryan Kohlenberg, Sr. Project Engineer photographs in this issue, Vacant, City of Boulder Steve Materkowski, Sr. Construction and additional photos and Vacant, Jefferson County Manager Finance and Accounting figures, can be seen on our Frank Dobbins, Manager web site at: Administrative Services www.udfcd.org Sandy Gonzalez, Manager Galene Bushor, Sr. Admin. Asst. FLOOD HAZARD NEWS Margaret Corkery, Admin. Asst. Bill DeGroot, Editor Geanesia Hinton, Receptionist

Public Service Co. (now Xcel Energy) substation at the The same view taken in August, 2005, showing the Confluence of Cherry Creek and the South Platte River, latest addition to Confluence Park. circa 1970